this is all extremely speculative, of course! but i would say that anything that affects your thinking can pose an evolutionary advantage or disadvantage. (to a

this is all extremely speculative, of course! but i would say that anything that affects your thinking can pose an evolutionary advantage or disadvantage. (to also answer a peer comment here:) including when you are past your reproductive age, since human beings are social beings, and our evolution cannot be regarded purely individualistically. to give an extremely stupid, but i hope illustrative example, a society where the old people go extremely stupid and start killing people around them is going to have a hard time ;)